Download - Getting Started With Abaqus

5/20/2015 2.3Example:creatingamodelofanoverheadhoist

http://mohammed_fakhir:2080/v6.14/books/gsa/ch02s03.html 1/31

2.3Example:creatingamodelofanoverheadhoist

Thisexampleofanoverheadhoist,showninFigure25,leadsyouthroughtheAbaqus/CAEmodelingprocessbyusingtheModelTreeandshowingyouthebasicstepsusedtocreateandanalyzeasimplemodel.Thehoistisasimple,pinjointedtrussmodelthatisconstrainedattheleftendandmountedonrollersattherightend.Thememberscanrotatefreelyatthejoints.Theframeispreventedfrommovingoutofplane.AsimulationisfirstperformedinAbaqus/Standardtodeterminethestructure'sstaticdeflectionandthepeakstressinitsmemberswhena10kNloadisappliedasshowninFigure25.ThesimulationisperformedasecondtimeinAbaqus/Explicitundertheassumptionthattheloadisappliedsuddenlytostudythedynamicresponseoftheframe.

Figure25Schematicofanoverheadhoist.

Fortheoverheadhoistexample,youwillperformthefollowingtasks:

Sketchthetwodimensionalgeometryandcreateapartrepresentingtheframe.

Definethematerialpropertiesandsectionpropertiesoftheframe.

Assemblethemodel.

Configuretheanalysisprocedureandoutputrequests.

Applyloadsandboundaryconditionstotheframe.

Meshtheframe.

Createajobandsubmititforanalysis.



Viewtheresultsoftheanalysis.

Abaqusprovidesscriptsthatreplicatethecompleteanalysismodelforthisproblem.Runoneofthesescriptsifyouencounterdifficultiesfollowingtheinstructionsgivenbeloworifyouwishtocheckyourwork.Scriptsareavailableinthefollowinglocations:

APythonscriptforthisexampleisprovidedinOverheadhoistframe,SectionA.1.InstructionsonhowtofetchthescriptandrunitwithinAbaqus/CAEaregiveninAppendixA,ExampleFiles.

ApluginscriptforthisexampleisavailableintheAbaqus/CAEPlugintoolset.TorunthescriptfromAbaqus/CAE,selectPlugins Abaqus GettingStartedhighlightOverheadhoistframeandclickRun.FormoreinformationabouttheGettingStartedplugins,seeRunningtheGettingStartedwithAbaqusexamples,Section82.1oftheAbaqus/CAEUser'sGuide.

Asnotedearlier,itisassumedthatyouwillbeusingAbaqus/CAEtogeneratethemodel.However,ifyoudonothaveaccesstoAbaqus/CAEoranotherpreprocessor,theinputfilethatdefinesthisproblemcanbecreatedmanually,asdiscussedinExample:creatingamodelofanoverheadhoist,Section2.3ofGettingStartedwithAbaqus:KeywordsEdition.

2.3.1Units

Beforestartingtodefinethisoranymodel,youneedtodecidewhichsystemofunitsyouwilluse.Abaqushasnobuiltinsystemofunits.DonotincludeunitnamesorlabelswhenenteringdatainAbaqus.Allinputdatamustbespecifiedinconsistentunits.SomecommonsystemsofconsistentunitsareshowninTable21.

Table21Consistentunits.

Quantity SI SI(mm) USUnit(ft) USUnit(inch)Length m mm ft inForce N N lbf lbfMass kg tonne(103kg) slug lbfs2/in

Time s s s sStress Pa(N/m2) MPa(N/mm2) lbf/ft2 psi(lbf/in2)

Energy J mJ(103J) ftlbf inlbf

Density kg/m3 tonne/mm3 slug/ft3 lbfs2/in4

TheSIsystemofunitsisusedthroughoutthisguide.UsersworkinginthesystemslabeledUSUnitshouldbecarefulwiththeunitsofdensityoftenthedensitiesgiveninhandbooksofmaterialpropertiesaremultipliedbytheaccelerationduetogravity.

2.3.2Creatingapart

Partsdefinethegeometryoftheindividualcomponentsofyourmodeland,therefore,arethebuildingblocksofanAbaqus/CAEmodel.YoucancreatepartsthatarenativetoAbaqus/CAE,oryoucanimportpartscreatedbyotherapplicationseitherasageometricrepresentationorasafiniteelementmesh.

Youwillstarttheoverheadhoistproblembycreatingatwodimensional,deformablewirepart.Youdothisbysketchingthegeometryoftheframe.Abaqus/CAEautomaticallyenterstheSketcherwhenyoucreateapart.

Abaqus/CAEoftendisplaysashortmessageinthepromptareaindicatingwhatyoushoulddonext,asshowninFigure26.

Figure26Messagesandinstructionsaredisplayedinthepromptarea.



ClicktheCancelbuttontocancelthecurrenttask.ClickthePreviousbuttontocancelthecurrentstepinthetaskandreturntothepreviousstep.

Tocreatetheoverheadhoistframe:

1. IfyoudidnotalreadystartAbaqus/CAE,typeabaquscae,whereabaqusisthecommandusedtorunAbaqus.

2. FromtheCreateModelDatabaseoptionsintheStartSessiondialogboxthatappears,selectWithStandard/ExplicitModel.

Abaqus/CAEentersthePartmodule.TheModelTreeappearsintheleftsideofthemainwindow(underneaththeModeltab).BetweentheModelTreeandthecanvasisthePartmoduletoolbox.Atoolboxcontainsasetoficonsthatallowexpertuserstobypassthemenusinthemainmenubar.Formanytools,asyouselectanitemfromthemainmenubarortheModelTree,thecorrespondingtoolishighlightedinthemoduletoolboxsoyoucanlearnitslocation.

3. IntheModelTree,doubleclickthePartscontainertocreateanewpart.

TheCreatePartdialogboxappears.Abaqus/CAEalsodisplaystextinthepromptareanearthebottomofthewindowtoguideyouthroughtheprocedure.

YouusetheCreatePartdialogboxtonametheparttochooseitsmodelingspace,type,andbasefeatureandtosettheapproximatesize.Youcaneditandrenameapartafteryoucreateityoucanalsochangeitsmodelingspaceandtypebutnotitsbasefeature.

4. NamethepartFrame.Chooseatwodimensionalplanardeformablebodyandawirebasefeature.

5. IntheApproximatesizetextfield,type4.0.

ThevalueenteredintheApproximatesizetextfieldatthebottomofthedialogboxsetstheapproximatesizeofthenewpart.ThesizethatyouenterisusedbyAbaqus/CAEtocalculatethesizeoftheSketchersheetandthespacingofitsgrid.Youshouldchoosethisvaluetobeontheorderofthelargestdimensionofyourfinishedpart.RecallthatAbaqus/CAEdoesnotusespecificunits,buttheunitsmustbeconsistentthroughoutthemodel.InthismodelSIunitswillbeused.

6. ClickContinuetoexittheCreatePartdialogbox.

Abaqus/CAEautomaticallyenterstheSketcher.TheSketchertoolboxappearsintheleftsideofthemainwindow,andtheSketchergridappearsintheviewport.TheSketchercontainsasetofbasictoolsthatallowyoutosketchthetwodimensionalprofileofyourpart.Abaqus/CAEenterstheSketcherwheneveryoucreateoreditapart.Tofinishusinganytool,clickmousebutton2intheviewportorselectanewtool.

Tip:LikealltoolsinAbaqus/CAE,ifyousimplypositionthecursoroveratoolintheSketchertoolboxforashorttime,asmallwindowappearsthatgivesabriefdescriptionofthetool.Whenyouselectatool,awhitebackgroundappearsonit.

ThefollowingaspectsoftheSketcherhelpyousketchthedesiredgeometry:

TheSketchergridhelpsyoupositionthecursorandalignobjectsintheviewport.

DashedlinesindicatetheXandYaxesofthesketchandintersectattheoriginofthesketch.



Atriadinthelowerleftcorneroftheviewportindicatestherelationshipbetweenthesketchplaneandtheorientationofthepart.

Whenyouselectasketchingtool,Abaqus/CAEdisplaystheXandYcoordinatesofthecursorintheupperleftcorneroftheviewport.

7. Youwillfirstsketcharoughapproximationoftheframeandlateruseconstraintsanddimensionstorefinethe

sketch.BeginbyusingtheCreateLines:Rectangletool locatedintheupperrightregionoftheSketchertoolboxtosketchanarbitraryrectangle.Selectanytwopointsastheoppositecornersoftherectangle.

Clickmousebutton2anywhereintheviewporttoexittherectangletool.

Note:IfyoumakeamistakewhileusingtheSketcher,youcanundoyourlastactionusingthe

Undotool ordeleteindividualentitiesofyoursketchusingtheDeletetool .

8. TheSketcherautomaticallyaddsconstraintstothesketchasindicatedinFigure27(inthiscase,thefourcornersoftherectangleareassignedperpendicularconstraintsandoneedgeisdesignatedashorizontal).

Figure27ConstraintsindicatedintheSketcher.

Toproceed,theperpendicularconstraintsmustbedeleted.IntheSketchertoolbox,selecttheDeletetool andthendothefollowing:

a. Inthepromptarea,selectConstraintsasthescopeoftheoperation.

b. Using[Shift]+Click,selectthefourperpendicularconstraints.

c. ClickDoneinthepromptarea.

9. Youwillnowaddadditionalconstraintsanddimensionstorefinethesketch.Constraintsanddimensionsallowyoutocontrolyoursketchgeometryandaddprecision.Formoreinformationonconstraintsanddimensions,seeControllingsketchgeometry,Section20.7oftheAbaqus/CAEUser'sGuide.

a. UsetheAddConstrainttool toconstrainthetopandbottomedgessotheyremainparalleltoeachother:

i. IntheAddConstraintdialogbox,selectParallel.

ii. Intheviewport,selectthetopandbottomedgesofthesketch(using[Shift]+Click).

iii. ClickDoneinthepromptarea.



b. UsetheAddDimensiontool todimensionthetopandbottomedgesoftherectangle.Thetopedgeshouldhaveahorizontaldimensionof1mandthebottomedgeahorizontaldimensionof2m.Whendimensioningeachedge,simplyselecttheline,clickmousebutton1topositionthedimensiontext,andthenenterthenewdimensioninthepromptarea.Selectingthelineratherthanitsendpointsconstrainsthelengthofthelineregardlessofitsorientationinspace(ineffect,defininganobliquedimension).

ResettheviewasneededusingtheAutoFitViewtool intheViewManipulationtoolbartoseetheupdatedsketch.

c. Dimensiontheleftandrightedgessotheyeachhaveanobliquedimensionof1m.

ThesketchinitscurrentstateisshowninFigure28.Inthisfigurethedefaultgridspacinghasbeendoubled.For

informationonusingtheSketcherOptionstool tomodifytheSketcherdisplay,seeCustomizingtheSketcher,Section20.9oftheAbaqus/CAEUser'sGuide.

Figure28Roughsketchofframe(withgridspacingdoubled).

10. Nowsketchtheinterioredgesoftheframe.

a. UsingtheCreateLines:Connectedtool locatedintheupperrightcorneroftheSketchertoolbox,createtwolinesasfollows:

i. Startthefirstlineattheupperleftcornerofthesketchandextendittoanypointthatsnapsontothebottomedge(itshorizontallocationisarbitrary).

ii. Continuethesecondlinetotheupperrightcornerofthesketch.

iii. Clickmousebutton2anywhereintheviewporttoexittheconnectedlinestool.

b. UsingtheSplittool ,splitthebottomedgeatthepointwhereitintersectsthetwolinescreatedabove:

i. Notethesmallblacktrianglesatthebaseofsomeofthetoolboxicons.Thesetrianglesindicatethe

presenceofhiddeniconsthatcanberevealed.ClickandholdtheAutoTrimtool locatedonthemiddlerightoftheSketchertoolboxuntiladditionaliconsappear.



ii. Fromthesetofadditionalicons,clicktheSplittool .

ThesplittoolappearsintheSketchertoolboxwithawhitebackgroundindicatingthatyouselectedit.

iii. Selectthebottomedgeasthefirstentitytodefinethesplitpoint.

iv. Selecteitherofthetwointeriorlinesasthesecondentity(aredcirclewillappeararoundthesplitpoint).

v. Clickmousebutton2toindicatethatyouhavefinishedusingthesplittool.

c. UsetheAddConstrainttool toconstrainthetwosegmentsofthebottomedgesotheyareofequallength:

i. IntheAddConstraintdialogbox,selectEquallength.

ii. Intheviewport,selectthetwosegmentsofthebottomedge.

iii. ClickDoneinthepromptarea.

11. ThefinalsketchisshowninFigure29.

Figure29Framegeometrysketch.

12. Fromthepromptarea(nearthebottomofthemainwindow),clickDonetoexittheSketcher.

Note:Ifyoudon'tseetheDonebuttoninthepromptarea,continuetoclickmousebutton2intheviewportuntilitappears.

13. Beforeyoucontinue,saveyourmodelinamodeldatabasefile.

a. Fromthemainmenubar,selectFile Save.TheSaveModelDatabaseAsdialogboxappears.

b. TypeanameforthenewmodeldatabaseintheFileNamefield,andclickOK.YoudonotneedtoincludethefileextensionAbaqus/CAEautomaticallyappends.caetothefilename.

Abaqus/CAEstoresthemodeldatabaseinanewfileandreturnstothePartmodule.Thepathandnameofyourmodeldatabaseappearinthemainwindowtitlebar.

Youshouldalwayssaveyourmodeldatabaseatregularintervals(forexample,eachtimeyouswitchmodules)



Abaqus/CAEdoesnotsaveyourmodeldatabaseautomatically.

2.3.3Creatingamaterial

InthisproblemallthemembersoftheframearemadeofsteelandassumedtobelinearelasticwithYoung'smodulusof200GPaandPoisson'sratioof0.3.Thus,youwillcreateasinglelinearelasticmaterialwiththeseproperties.

Todefineamaterial:

1. IntheModelTree,doubleclicktheMaterialscontainertocreateanewmaterial.

Abaqus/CAEswitchestothePropertymodule,andtheEditMaterialdialogboxappears.

2. NamethematerialSteel.

3. Usethemenubarunderthebrowserareaofthematerialeditortorevealmenuscontainingalltheavailablematerialoptions.Someofthemenuitemscontainsubmenusforexample,Figure210showstheoptionsavailableundertheMechanical Elasticitymenuitem.Whenyouselectamaterialoption,theappropriatedataentryformappearsbelowthemenu.

Figure210SubmenusavailableundertheMechanical Elasticitymenu.

4. Fromthematerialeditor'smenubar,selectMechanical Elasticity Elastic.

Abaqus/CAEdisplaystheElasticdataform.

5. Typeavalueof200.0E9forYoung'smodulusandavalueof0.3forPoisson'sratiointherespectivefields.Use[Tab]ormovethecursortoanewcellandclicktomovebetweencells.

6. ClickOKtoexitthematerialeditor.

2.3.4Definingandassigningsectionproperties

Youdefinethepropertiesofapartthroughsections.Afteryoucreateasection,youcanuseoneofthefollowingtwomethodstoassignthesectiontothepartinthecurrentviewport:

Youcansimplyselecttheregionfromthepartandassignthesectiontotheselectedregion.

YoucanusetheSettoolsettocreateahomogeneoussetcontainingtheregionandassignthesectiontotheset.

Fortheframemodelyouwillcreateasingletrusssectionthatyouwillassigntotheframebyselectingtheframefromtheviewport.ThesectionwillrefertothematerialSteelthatyoujustcreatedaswellasdefinethecrosssectionalarea



oftheframemembers.

Definingatrusssection

Atrusssectiondefinitionrequiresonlyamaterialreferenceandthecrosssectionalarea.Rememberthattheframemembersarecircularbarsthatare0.005mindiameter.Thus,theircrosssectionalareais1.963105

m2.

Tip:Youcanusethecommandlineinterface(CLI)inAbaqus/CAEasasimplecalculator.Forexample,tocomputethecrosssectionalareaoftheframemembers,clickthe tabinthebottomleftcorneroftheAbaqus/CAEwindowtoactivatetheCLI,typepi*0.005**2/4.0afterthecommandprompt,andpress[Enter].ThevalueofthecrosssectionalareaisprintedintheCLI.

Todefineatrusssection:

1. IntheModelTree,doubleclicktheSectionscontainertocreateasection.

TheCreateSectiondialogboxappears.

2. IntheCreateSectiondialogbox:

a. NamethesectionFrameSection.

b. IntheCategorylist,selectBeam.

c. IntheTypelist,selectTruss.

d. ClickContinue.

TheEditSectiondialogboxappears.

3. IntheEditSectiondialogbox:

a. AcceptthedefaultselectionofSteelfortheMaterialassociatedwiththesection.Ifyouhaddefinedothermaterials,youcouldclickthearrownexttotheMaterialtextboxtoseealistofavailablematerialsandtoselectthematerialofyourchoice.

b. IntheCrosssectionalareafield,enterpi*0.005**2/4.0.

Tip:Ifafieldinadialogboxisexpectingafloatingpointnumber,youcanenteranarithmeticexpressioninstead.TheexpressionisevaluatedbythePythoninterpreterthatisbuiltintoAbaqus/CAE.Thearithmeticexpressionwillbereplacedbyitsvalue.

c. ClickOK.

Assigningthesectiontotheframe

ThesectionFrameSectionmustbeassignedtotheframe.

Toassignthesectiontotheframe:

1. IntheModelTree,expandthebranchforthepartnamedFramebyclickingthe symboltoexpandthePartscontainerandthenclickingthe symboltoexpandtheFrameitem.

2. DoubleclickSectionAssignmentsinthelistofpartattributesthatappears.

Abaqus/CAEdisplayspromptsinthepromptareatoguideyouthroughtheprocedure.



3. Selecttheentirepartastheregiontowhichthesectionwillbeapplied.

a. Clickandholdmousebutton1attheupperlefthandcorneroftheviewport.

b. Dragthemousetocreateaboxaroundthetruss.

c. Releasemousebutton1.

Abaqus/CAEhighlightstheentireframe.

4. Inthepromptarea,enterallasthenameofthesetthatwillbecreated.

Thissetwillcontaintheselectedregions.Theadvantageofcreatingasetisthatitcanbeusedforotherpurposes.Ifyouprefertonotcreateaset,toggleoffCreatesetinthepromptarea.

5. Clickmousebutton2intheviewportorclickDoneinthepromptareatoaccepttheselectedgeometry.

TheEditSectionAssignmentdialogboxappearscontainingalistofexistingsections.

6. AcceptthedefaultselectionofFrameSection,andclickOK.

Abaqus/CAEassignsthetrusssectiontotheframe,colorstheentireframeaquatoindicatethattheregionhasasectionassignment,andclosestheEditSectionAssignmentdialogbox.

2.3.5Definingtheassembly

Eachpartthatyoucreateisorientedinitsowncoordinatesystemandisindependentoftheotherpartsinthemodel.Althoughamodelmaycontainmanyparts,itcontainsonlyoneassembly.Youdefinethegeometryoftheassemblybycreatinginstancesofapartandthenpositioningtheinstancesrelativetoeachotherinaglobalcoordinatesystem.Aninstancecanbeclassifiedaseitherindependentordependent.Independentpartinstancesaremeshedindividually,whilethemeshofadependentpartinstanceisassociatedwiththemeshoftheoriginalpart.Forfurtherdetails,seeWorkingwithpartinstances,Section13.3oftheAbaqus/CAEUser'sGuide.Bydefault,partinstancesaredependent.

Forthisproblemyouwillcreateasingleinstanceofyouroverheadhoist.Abaqus/CAEpositionstheinstancesothattheoriginofthesketchthatdefinedtheframeoverlaystheoriginoftheassembly'sdefaultcoordinatesystem.

Todefinetheassembly:

1. IntheModelTree,expandtheAssemblycontaineranddoubleclickInstancesinthelistthatappears.

Abaqus/CAEswitchestotheAssemblymodule,andtheCreateInstancedialogboxappears.

2. Inthedialogbox,selectPartstochoosepartsfromthecurrentmodel.

3. SelectFrameandclickOK.

Abaqus/CAEcreatesaninstanceoftheoverheadhoist.Inthisexamplethesingleinstanceoftheframedefinestheassembly.Theframeisdisplayedinthe12planeoftheglobalcoordinatesystem(arighthanded,rectangularCartesiansystem).Atriadinthelowerleftcorneroftheviewportindicatestheorientationofthemodelwithrespecttotheview.Asecondtriadintheviewportindicatestheoriginandorientationoftheglobalcoordinatesystem(X,Y,andZaxes).Theglobal1axisisthehorizontalaxisofthehoist,theglobal2axisistheverticalaxis,andtheglobal3axisisnormaltotheplaneoftheframework.FortwodimensionalproblemssuchasthisoneAbaqusrequiresthatthemodellieinaplaneparalleltotheglobal12plane.

2.3.6Configuringyouranalysis

Nowthatyouhavecreatedyourassembly,youcanconfigureyouranalysis.Inthissimulationweareinterestedinthestaticresponseoftheoverheadhoisttoa10kNloadappliedatthemidspan,withthelefthandendfullyconstrainedand



arollerconstraintontherighthandend(seeFigure25).Thisisasingleevent,soonlyasingleanalysisstepisneededforthesimulation.Thus,themodelwillconsistoftwostepsoverall:

Aninitialstep,inwhichyouwillapplyboundaryconditionsthatconstraintheendsoftheframe.

Ananalysisstep,inwhichyouwillapplyaconcentratedloadatthemidspanoftheframe.

Abaqus/CAEgeneratestheinitialstepautomatically,butyoumustcreatetheanalysisstepyourself.Youmayalsorequestoutputforanystepsintheanalysis.

TherearetwokindsofanalysisstepsinAbaqus:generalanalysissteps,whichcanbeusedtoanalyzelinearornonlinearresponse,andlinearperturbationsteps,whichcanbeusedonlytoanalyzelinearproblems.OnlygeneralanalysisstepsareavailableinAbaqus/Explicit.Forthissimulationyouwilldefineastaticlinearperturbationstep.PerturbationproceduresarediscussedfurtherinChapter11,MultipleStepAnalysis.

Creatingananalysisstep

Createastatic,linearperturbationstepthatfollowstheinitialstepoftheanalysis.

Tocreateastaticlinearperturbationanalysisstep:

1. IntheModelTree,doubleclicktheStepscontainertocreateastep.

Abaqus/CAEswitchestotheStepmodule,andtheCreateStepdialogboxappears.AlistofallthegeneralproceduresandadefaultstepnameofStep1isprovided.

2. ChangethestepnametoApplyload.

3. SelectLinearperturbationastheProceduretype.

4. FromthelistofavailablelinearperturbationproceduresintheCreateStepdialogbox,selectStatic,LinearperturbationandclickContinue.

TheEditStepdialogboxappearswiththedefaultsettingsforastaticlinearperturbationstep.

5. TheBasictabisselectedbydefault.IntheDescriptionfield,type10kNcentralload.

6. ClicktheOthertabtoseeitscontentsyoucanacceptthedefaultvaluesprovidedforthestep.

7. ClickOKtocreatethestepandtoexittheEditStepdialogbox.

Requestingdataoutput

Finiteelementanalysescancreateverylargeamountsofoutput.Abaqusallowsyoutocontrolandmanagethisoutputsothatonlydatarequiredtointerprettheresultsofyoursimulationareproduced.FourtypesofoutputareavailablefromanAbaqusanalysis:

ResultsstoredinaneutralbinaryfileusedbyAbaqus/CAEforpostprocessing.ThisfileiscalledtheAbaqusoutputdatabasefileandhastheextension.odb.

Printedtablesofresults,writtentotheAbaqusdata(.dat)file.OutputtothedatafileisavailableonlyinAbaqus/Standard.

Restartdatausedtocontinuetheanalysis,writtentotheAbaqusrestart(.res)file.

Resultsstoredinbinaryfilesforsubsequentpostprocessingwiththirdpartysoftware,writtentotheAbaqusresults(.fil)file.

Youwilluseonlythefirstoftheseintheoverheadhoistsimulation.



Bydefault,Abaqus/CAEwritestheresultsoftheanalysistotheoutputdatabase(.odb)file.Whenyoucreateastep,Abaqus/CAEgeneratesadefaultoutputrequestforthestep.AlistofthepreselectedvariableswrittenbydefaulttotheoutputdatabaseisgivenintheAbaqusAnalysisUser'sGuide.Youdonotneedtodoanythingtoacceptthesedefaults.YouusetheFieldOutputRequestsManagertorequestoutputofvariablesthatshouldbewrittenatrelativelylowfrequenciestotheoutputdatabasefromtheentiremodelorfromalargeportionofthemodel.YouusetheHistoryOutputRequestsManagertorequestoutputofvariablesthatshouldbewrittentotheoutputdatabaseatahighfrequencyfromasmallportionofthemodelforexample,thedisplacementofasinglenode.

Forthisexampleyouwillexaminetheoutputrequeststothe.odbfileandacceptthedefaultconfiguration.

Toexamineyouroutputrequeststothe.odbfile:

1. IntheModelTree,clickmousebutton3ontheFieldOutputRequestscontainerandselectManagerfromthemenuthatappears.

Abaqus/CAEdisplaystheFieldOutputRequestsManager.Thismanagerdisplaysthestatusoffieldoutputrequestsinatableformat.Theleftsideofthetablehasanalphabeticallistofexistingoutputrequests.Thetopofthetableliststhenamesofallthestepsintheanalysisintheorderofexecution.Eachcellofthetabledisplaysthestatusofeachoutputrequestineachstep.

YoucanusetheFieldOutputRequestsManagertodothefollowing:

SelectthevariablesthatAbaquswillwritetotheoutputdatabase.

SelectthesectionpointsforwhichAbaquswillgenerateoutputdata.

SelecttheregionofthemodelforwhichAbaquswillgenerateoutputdata.

ChangethefrequencyatwhichAbaquswillwritedatatotheoutputdatabase.

2. ReviewthedefaultoutputrequestthatAbaqus/CAEgeneratesfortheStatic,LinearperturbationstepyoucreatedandnamedApplyload.

SelectthecellinthetablelabeledCreatedifitisnotalreadyselected.Thefollowinginformationrelatedtothecellisshowninthelegendatthebottomofthemanager:

Thetypeofanalysisprocedurecarriedoutinthestepinthatcolumn.

Thelistofoutputrequestvariables.

Theoutputrequeststatus.

3. OntherightsideoftheFieldOutputRequestsManager,clickEdittoviewmoredetailedinformationabouttheoutputrequest.

Thefieldoutputeditorappears.IntheOutputVariablesregionofthisdialogbox,thereisatextboxthatlistsallvariablesthatwillbeoutput.Ifyouchangeanoutputrequest,youcanalwaysreturntothedefaultsettingsbychoosingPreselecteddefaultsabovethetextbox.

4. Clickthearrowsnexttoeachoutputvariablecategorytoseeexactlywhichvariableswillbeoutput.Theboxesnexttoeachcategorytitleallowyoutoseeataglancewhetherallvariablesinthatcategorywillbeoutput.Ablackcheckmarkindicatesthatallvariablesareoutput,whileagraycheckmarkindicatesthatonlysomevariableswillbeoutput.

Basedontheselectionsshownatthebottomofthedialogbox,datawillbegeneratedateverydefaultsectionpointinthemodelandwillbewrittentotheoutputdatabaseaftereveryincrementduringtheanalysis.



5. ClickCanceltoclosethefieldoutputeditor,sinceyoudonotwishtomakeanychangestothedefaultoutputrequests.

6. ClickDismisstoclosetheFieldOutputRequestsManager.

Note:WhatisthedifferencebetweentheDismissandCancelbuttons?Dismissbuttonsappearindialogboxesthatcontaindatathatyoucannotmodify.Forexample,theFieldOutputRequestsManagerallowsyoutoviewoutputrequests,butyoumustusethefieldoutputeditortomodifythoserequests.ClickingtheDismissbuttonsimplyclosestheFieldOutputRequestsManager.Conversely,Cancelbuttonsappearindialogboxesthatallowyoutomakechanges.ClickingCancelclosesthedialogboxwithoutsavingyourchanges.

7. ReviewthehistoryoutputrequestsinasimilarmannerbyrightclickingtheHistoryOutputRequestscontainerintheModelTreeandopeningthehistoryoutputeditor.

2.3.7Applyingboundaryconditionsandloadstothemodel

Prescribedconditions,suchasloadsandboundaryconditions,arestepdependent,whichmeansthatyoumustspecifythesteporstepsinwhichtheybecomeactive.Nowthatyouhavedefinedthestepsintheanalysis,youcandefineprescribedconditions.

Applyingboundaryconditionstotheframe

Instructuralanalyses,boundaryconditionsareappliedtothoseregionsofthemodelwherethedisplacementsand/orrotationsareknown.Suchregionsmaybeconstrainedtoremainfixed(havezerodisplacementand/orrotation)duringthesimulationormayhavespecified,nonzerodisplacementsand/orrotations.

Inthismodelthebottomleftportionoftheframeisconstrainedcompletelyand,thus,cannotmoveinanydirection.Thebottomrightportionoftheframe,however,isfixedintheverticaldirectionbutisfreetomoveinthehorizontaldirection.Thedirectionsinwhichmotionispossiblearecalleddegreesoffreedom(dof).

ThelabelingconventionusedforthedisplacementandrotationaldegreesoffreedominAbaqusisshowninFigure211.

Figure211Displacementandrotationaldegreesoffreedom.

Toapplyboundaryconditionstotheframe:

1. IntheModelTree,doubleclicktheBCscontainer.

Abaqus/CAEswitchestotheLoadmodule,andtheCreateBoundaryConditiondialogboxappears.

2. IntheCreateBoundaryConditiondialogbox:

a. NametheboundaryconditionFixed.



b. Fromthelistofsteps,selectInitialasthestepinwhichtheboundaryconditionwillbeactivated.AllthemechanicalboundaryconditionsspecifiedintheInitialstepmusthavezeromagnitudes.ThisconditionisenforcedautomaticallybyAbaqus/CAE.

c. IntheCategorylist,acceptMechanicalasthedefaultcategoryselection.

d. IntheTypesforSelectedSteplist,selectDisplacement/Rotation,andclickContinue.

Abaqus/CAEdisplayspromptsinthepromptareatoguideyouthroughtheprocedure.Forexample,youareaskedtoselecttheregiontowhichtheboundaryconditionwillbeapplied.

Toapplyaprescribedconditiontoaregion,youcaneitherselecttheregiondirectlyintheviewportorapplytheconditiontoanexistingset(asetisanamedregionofamodel).Setsareaconvenienttoolthatcanbeusedtomanagelargecomplicatedmodels.Inthissimplemodelyouwillnotmakeuseofsets.

3. Intheviewport,selectthevertexatthebottomleftcorneroftheframeastheregiontowhichtheboundaryconditionwillbeapplied.Nametheassociatedsetleft.

4. Clickmousebutton2intheviewportorclickDoneinthepromptareatoindicatethatyouhavefinishedselectingregions.

TheEditBoundaryConditiondialogboxappears.Whenyouaredefiningaboundaryconditionintheinitialstep,allavailabledegreesoffreedomareunconstrainedbydefault.

5. Inthedialogbox:

a. ToggleonU1andU2sincealltranslationaldegreesoffreedomneedtobeconstrained.

b. ClickOKtocreatetheboundaryconditionandtoclosethedialogbox.

Abaqus/CAEdisplaystwoarrowheadsatthevertextoindicatetheconstraineddegreesoffreedom.

6. RepeattheaboveproceduretoconstraindegreeoffreedomU2atthevertexatthebottomrightcorneroftheframe.NamethisboundaryconditionRollerandtheassociatedsetright.

7. IntheModelTree,clickmousebutton3ontheBCscontainerandselectManagerfromthemenuthatappears.

Abaqus/CAEdisplaystheBoundaryConditionManager.ThemanagerindicatesthattheboundaryconditionsareCreated(activated)intheinitialstepandarePropagatedfrombasestate(continuetobeactive)intheanalysisstepApplyload.

Tip:Toviewthetitleofacolumninitsentirety,expanditswidthbydraggingthedividinglinebetweenthecolumnheadings.

8. ClickDismisstoclosetheBoundaryConditionManager.

Inthisexamplealltheconstraintsareintheglobal1or2directions.Inmanycasesconstraintsarerequiredindirectionsthatarenotalignedwiththeglobaldirections.Insuchcasesyoucandefinealocalcoordinatesystemforboundaryconditionapplication.TheskewplateexampleinChapter5,UsingShellElements,demonstrateshowtodothis.

Applyingaloadtotheframe

Nowthatyouhaveconstrainedtheframe,youcanapplyaloadtothebottomoftheframe.InAbaqusthetermload(asintheLoadmoduleinAbaqus/CAE)generallyreferstoanythingthatinducesachangeintheresponseofastructurefromitsinitialstate,including:



concentratedforces,

pressures,

nonzeroboundaryconditions,

bodyloads,and

temperature(withthermalexpansionofthematerialdefined).

Sometimesthetermloadisusedtoreferspecificallytoforcetypequantities(asintheLoadManageroftheLoadmodule)forexample,concentratedforces,pressures,andbodyloadsbutnotboundaryconditionsortemperature.Theintendedmeaningofthetermshouldbeclearfromthecontextofthediscussion.

Inthissimulationaconcentratedforceof10kNisappliedinthenegative2directiontothemidspanoftheframetheloadisappliedduringthelinearperturbationstepyoucreatedearlier.Inrealitythereisnosuchthingasaconcentrated,orpoint,loadtheloadwillalwaysbeappliedoversomefinitearea.However,iftheareabeingloadedissmall,itisanappropriateidealizationtotreattheloadasaconcentratedload.

Toapplyaconcentratedforcetotheframe:

1. IntheModelTree,clickmousebutton3ontheLoadscontainerandselectManagerfromthemenuthatappears.

TheLoadManagerappears.

2. AtthebottomoftheLoadManager,clickCreate.

TheCreateLoaddialogboxappears.

3. IntheCreateLoaddialogbox:

a. NametheloadForce.

b. Fromthelistofsteps,selectApplyloadasthestepinwhichtheloadwillbeapplied.

c. IntheCategorylist,acceptMechanicalasthedefaultcategoryselection.

d. IntheTypesforSelectedSteplist,acceptthedefaultselectionofConcentratedforce.

e. ClickContinue.

Abaqus/CAEdisplayspromptsinthepromptareatoguideyouthroughtheprocedure.Youareaskedtoselectaregiontowhichtheloadwillbeapplied.

Aswithboundaryconditions,theregiontowhichtheloadwillbeappliedcanbeselectedeitherdirectlyintheviewportorfromalistofexistingsets.Asbefore,youwillselecttheregiondirectlyintheviewport.

4. Intheviewport,selectthevertexatthebottomcenteroftheframeastheregionwheretheloadwillbeapplied.Nametheassociatedsetcenter.

5. Clickmousebutton2intheviewportorclickDoneinthepromptareatoindicatethatyouhavefinishedselectingregions.

TheEditLoaddialogboxappears.

6. Inthedialogbox:

a. Enteramagnitudeof10000.0forCF2.



b. ClickOKtocreatetheloadandtoclosethedialogbox.

Abaqus/CAEdisplaysadownwardpointingarrowatthevertextoindicatethattheloadisappliedinthenegative2direction.

7. ExaminetheLoadManagerandnotethatthenewloadisCreated(activated)intheanalysisstepApplyload.

8. ClickDismisstoclosetheLoadManager.

2.3.8Meshingthemodel

Youwillnowgeneratethefiniteelementmesh.YoucanchoosethemeshingtechniquethatAbaqus/CAEwillusetocreatethemesh,theelementshape,andtheelementtype.Themeshingtechniqueforonedimensionalregions(suchastheonesinthisexample)cannotbechanged,however.Abaqus/CAEusesanumberofdifferentmeshingtechniques.ThedefaultmeshingtechniqueassignedtothemodelisindicatedbythecolorofthemodelthatisdisplayedwhenyouentertheMeshmoduleifAbaqus/CAEdisplaysthemodelinorange,itcannotbemeshedwithoutassistancefromyou.

AssigninganAbaquselementtype

InthissectionyouwillassignaparticularAbaquselementtypetothemodel.Althoughyouwillassigntheelementtypenow,youcouldalsowaituntilafterthemeshhasbeencreated.

Twodimensionaltrusselementswillbeusedtomodeltheframe.Theseelementsarechosenbecausetrusselements,whichcarryonlytensileandcompressiveaxialloads,areidealformodelingpinjointedframeworkssuchasthisoverheadhoist.

ToassignanAbaquselementtype:

1. IntheModelTree,expandtheFrameitemunderneaththePartscontainerifitisnotalreadyexpanded.ThendoubleclickMeshinthelistthatappears.

Abaqus/CAEswitchestotheMeshmodule.TheMeshmodulefunctionalityisavailableonlythroughmenubaritemsortoolboxicons.

2. Fromthemainmenubar,selectMesh ElementType.

3. Ifyoucreatedthesetnamedallwhileassigningsectionproperties,clickSetsintherightsideofthepromptareaandselectallfromtheRegionSelectiondialogbox.Otherwise,dragthemousetocreateaboxthatselectstheentireframeastheregiontobeassignedanelementtypeandclickDoneinthepromptareawhenyouarefinished.

TheElementTypedialogboxappears.

4. Inthedialogbox,selectthefollowing:

StandardastheElementLibraryselection(thedefault).

LinearastheGeometricOrder(thedefault).

TrussastheFamilyofelements.

5. Inthelowerportionofthedialogbox,examinetheelementshapeoptions.Abriefdescriptionofthedefaultelementselectionisavailableatthebottomofeachtabbedpage.

Sincethemodelisatwodimensionaltruss,onlytwodimensionaltrusselementtypesareshownontheLinetabbedpage.AdescriptionoftheelementtypeT2D2appearsatthebottomofthedialogbox.Abaqus/CAEwillnowassociateT2D2elementswiththeelementsinthemesh.



6. ClickOKtoassigntheelementtypeandtoclosethedialogbox.

7. Inthepromptarea,clickDonetoendtheprocedure.

Creatingthemesh

Basicmeshingisatwostageoperation:firstyouseedtheedgesofthepartinstance,andthenyoumeshthepartinstance.Youselectthenumberofseedsbasedonthedesiredelementsizeoronthenumberofelementsthatyouwantalonganedge,andAbaqus/CAEplacesthenodesofthemeshattheseedswheneverpossible.Forthisproblemyouwillcreateoneelementoneachbarofthehoist.

Toseedandmeshthemodel:

1. Fromthemainmenubar,selectSeed Parttoseedthepartinstance.

Note:Youcangainmorecontroloftheresultingmeshbyseedingeachedgeofthepartinstanceindividually,butitisnotnecessaryforthisexample.

TheGlobalSeedsdialogboxappears.ThedialogboxdisplaysthedefaultelementsizethatAbaqus/CAEwillusetoseedthepartinstance.Thisdefaultelementsizeisbasedonthesizeofthepartinstance.Arelativelylargeseedvaluewillbeusedsothatonlyoneelementwillbecreatedperregion.

2. IntheGlobalSeedsdialogbox,specifyanapproximateglobalelementsizeof1.0,andclickOKtocreatetheseedsandtoclosethedialogbox.

3. Fromthemainmenubar,selectMesh Parttomeshthepartinstance.

4. Fromthebuttonsinthepromptarea,clickYestoconfirmthatyouwanttomeshthepartinstance.

Tip:YoucandisplaythenodeandelementnumberswithintheMeshmodulebyselectingViewPartDisplayOptionsfromthemainmenubar.ToggleonShownodelabelsandShow

elementlabelsintheMeshtabbedpageofthePartDisplayOptionsdialogboxthatappears.

2.3.9Creatingananalysisjob

Nowthatyouhaveconfiguredyouranalysis,youwillcreateajobthatisassociatedwithyourmodel.

Tocreateananalysisjob:

1. IntheModelTree,doubleclicktheJobscontainertocreateajob.

Abaqus/CAEswitchestotheJobmodule,andtheCreateJobdialogboxappearswithalistofthemodelsinthemodeldatabase.Whenyouarefinisheddefiningyourjob,theJobscontainerwilldisplayalistofyourjobs.

2. NamethejobFrame,andclickContinue.

TheEditJobdialogboxappears.

3. IntheDescriptionfield,typeTwodimensionaloverheadhoistframe.

4. ClickOKtoacceptallotherdefaultjobsettingsinthejobeditorandtoclosethedialogbox.

2.3.10Checkingthemodel

Havinggeneratedthemodelforthissimulation,youarereadytoruntheanalysis.Unfortunately,itispossibletohaveerrorsinthemodelbecauseofincorrectormissingdata.Youshouldperformadatacheckanalysisfirstbeforerunningthesimulation.



Torunadatacheckanalysis:

1. IntheModelTree,expandtheJobscontainer.Clickmousebutton3onthejobnamedFrame,andselectDataCheckfromthemenuthatappearstosubmityourjobforadatacheckanalysis.

2. Afteryousubmityourjob,informationappearsnexttothejobnameindicatingthejob'sstatus.Thestatusoftheoverheadhoistproblemindicatesoneofthefollowingconditions:

CheckSubmittedwhilethemodelisbeingsubmittedforadatacheck.

CheckRunningwhileAbaqusperformsadatacheckonthemodel.

CheckCompletedwhenthedatacheckhascompletedsuccessfully.

Submittedwhilethejobisbeingsubmittedforafullanalysis.

RunningwhileAbaqusanalyzesthemodel.

Completedwhenthefullanalysisiscomplete,andtheoutputhasbeenwrittentotheoutputdatabase.

AbortedifAbaqus/CAEfindsaproblemwiththeinputfileortheanalysisandabortstheanalysis.Inaddition,Abaqus/CAEreportstheprobleminthemessagearea(seeFigure22).

Duringtheanalysis,Abaqus/StandardsendsinformationtoAbaqus/CAEtoallowyoutomonitortheprogressofthejob.Informationfromthestatus,data,log,andmessagefilesappearsintheJobMonitordialogbox.YoucanbrowsethesefilesinthetabbedwindowsinthebottomhalfoftheJobMonitordialogbox,andyoucansearchtheircontents.Selectthedesiredfiletab,enterasearchstringintheTexttofindfield,andclickNextorPrevioustostepthroughthefilefromonehittothenext.ToggleonMatchcasetoperformacasesensitivesearch.

Tomonitorthestatusofajob:

1. IntheModelTree,clickmousebutton3onthejobnamedFrameandselectMonitorfromthemenuthatappearstoopentheJobMonitordialogbox.

TheJobMonitordialogboxappears.

2. Thetophalfofthedialogboxdisplaystheinformationavailableinthestatus(.sta)filethatAbaquscreatesfortheanalysis.ThisfilecontainsabriefsummaryoftheprogressofananalysisandisdescribedinOutput,Section4.1.1oftheAbaqusAnalysisUser'sGuide.Thebottomhalfofthedialogboxallowsyoutoviewinformationabouttheanalysis.

ClicktheLogtabtodisplaythestartandendtimesfortheanalysisthatappearinthelog(.log)file.

ClicktheErrorsandWarningstabstodisplaytheerrorsorthewarningsthatappearinthedata(.dat)andmessage(.msg)files.Ifaparticularregionofthemodeliscausingtheerrororwarning,anodeorelementsetwillbecreatedautomaticallythatcontainsthatregion.Thenameofthenodeorelementsetappearswiththeerrororwarningmessage,andyoucanviewthesetusingdisplaygroupsintheVisualizationmodule.

Itwillnotbepossibletoperformtheanalysisuntilthecausesofanyerrormessagesarecorrected.Inaddition,youshouldalwaysinvestigatethereasonforanywarningmessagestodeterminewhethercorrectiveactionisneededorwhethersuchmessagescanbeignoredsafely.

Abaquslimitsthenumberoferrorandwarningmessagesthatappearinthejobmonitor(bydefaulttheselimitsare10errormessagesand50warningmessages).Ifthemessagelimitsareexceeded,informationregardingtheadditionalerrorsandwarningscanbeobtainedfromtheprintedoutputfilesthemselves.SeeJobcustomizationparameters,Section4.1.3oftheAbaqusInstallationandLicensingGuide,fordetailsonchangingthedefaultmessagelimits.

ClicktheOutputtabtodisplayarecordofeachoutputdataentryasitiswrittentotheoutputdatabase.



AstheanalysisproceedsandAbaquscreatesthedata,message,andstatusfiles,Abaqus/CAEactivatestheDataFile,MessageFile,andStatusFiletabsanddisplaysthecontentsofeachfileinthecorrespondingtabbedpage.Youcanclickanyofthesetabstobrowseorsearchthefileforadditionalerrorandwarningmessages.

Note:AlthoughAbaqus/CAEupdatesthecontentsoftheDataFile,MessageFile,andStatusFiletabbedpagesperiodicallyastheanalysisruns,thedatamightnotalwaysbesynchronizedwiththelatestdatainthefiles.

3. ClickDismisstoclosetheJobMonitordialogbox.

2.3.11Runningtheanalysis

Makeanynecessarycorrectionstoyourmodel.Whenthedatacheckanalysiscompleteswithnoerrormessages,runtheanalysisitself.Todothis,clickmousebutton3onthejobnamedFrameandselectContinuefromthemenuthatappears.

Note:Performingadatacheckanalysisresultsinthecreationofjobfiles.Whenyousubmitajobforanalysisandfilesofthesamenamealreadyexist,Abaqus/CAEdisplaysadialogboxaskingifitisOKtooverwritethejobfiles.ClickOKtocontinue.

Youshouldalwaysperformadatacheckanalysisbeforerunningasimulationtoensurethatthemodelhasbeendefinedcorrectlyandtocheckthatthereisenoughdiskspaceandmemoryavailabletocompletetheanalysis.However,itispossibletocombinethedatacheckandanalysisphasesofthesimulationbyclickingmousebutton3onthejobnameintheJobscontainerandselectingSubmitfromthemenuthatappears.

Ifasimulationisexpectedtotakeasubstantialamountoftime,itmaybeconvenienttorunitinabatchqueuebyselectingQueueastheRunModeintheEditJobdialogbox.(TheavailabilityofsuchaqueuedependsonthequeuedefinitionsettingsinyourAbaqusenvironmentfile.Ifyouhaveanyquestions,refertoDefininganalysisbatchqueues,Section4.2oftheAbaqusInstallationandLicensingGuide,oraskyoursystemadministratoraboutdefininganalysisbatchqueuesonyoursystem.)

2.3.12Postprocessing

Graphicalpostprocessingisimportantbecauseofthegreatvolumeofdatacreatedduringasimulation.TheVisualizationmoduleofAbaqus/CAE(alsolicensedseparatelyasAbaqus/Viewer)allowsyoutoviewtheresultsgraphicallyusingavarietyofmethods,includingdeformedshapeplots,contourplots,vectorplots,animations,andXYplots.Inaddition,itallowsyoutocreatetabularreportsoftheoutputdata.Allofthesemethodsarediscussedinthisguide.Formoreinformationonanyofthepostprocessingfeaturesdiscussedinthisguide,consultPartV,Viewingresults,oftheAbaqus/CAEUser'sGuide.ForthisexampleyouwillusetheVisualizationmoduletodosomebasicmodelchecksandtodisplaythedeformedshapeoftheframe.

Whenthejobcompletessuccessfully,youarereadytoviewtheresultsoftheanalysiswiththeVisualizationmodule.IntheModelTree,clickmousebutton3onthejobnamedFrameandselectResultsfromthemenuthatappearstoentertheVisualizationmodule.Abaqus/CAEopenstheoutputdatabasecreatedbythejobanddisplaystheundeformedmodelshape,asshowninFigure212.

Figure212Undeformedmodelshape.



YoucanalsoentertheVisualizationmodulebyselectingVisualizationfromtheModulelistlocatedinthecontextbar.SelectFile Open,selectFrame.odbfromthelistofavailableoutputdatabasefiles,andclickOK.

YoucanchoosetodisplaythetitleblockandstateblockatthebottomoftheviewporttheseblocksarenotshowninFigure212.Thetitleblockatthebottomoftheviewportindicatesthefollowing:

Thedescriptionofthemodel(fromthejobdescription).

Thenameoftheoutputdatabase(fromthenameoftheanalysisjob).

Theproductname(Abaqus/StandardorAbaqus/Explicit)andreleaseusedtogeneratetheoutputdatabase.

Thedatetheoutputdatabasewaslastmodified.

Thestateblockatthebottomoftheviewportindicatesthefollowing:

Whichstepisbeingdisplayed.

Theincrementwithinthestep.

Thesteptime.

Thevieworientationtriadindicatestheorientationofthemodelintheglobalcoordinatesystem.The3Dcompasslocatedintheupperrightcorneroftheviewportallowsyoutomanipulatetheviewdirectly.

Youcansuppressthedisplayofandcustomizethetitleblock,stateblock,vieworientationtriad,and3DcompassbyselectingViewport ViewportAnnotationOptionsfromthemainmenubar(forexample,manyofthefiguresinthisguidedonotincludethetitleblockorthecompass).

TheResultsTree

YouwillusetheResultsTreetoquerythecomponentsofthemodel.TheResultsTreeallowseasyaccesstothehistoryoutputcontainedinanoutputdatabasefileforthepurposeofcreatingXYplotsandalsotogroupsofelements,nodes,andsurfacesbasedonsetnames,materialandsectionassignment,etc.forthepurposesofverifyingthemodelandalsocontrollingtheviewportdisplay.

Toquerythemodel:



1. Intheleftsideofthemainwindow,clicktheResultstabtoswitchtotheResultsTreeifitisnotalreadyvisible.

2. AlloutputdatabasefilesthatareopeninagivenpostprocessingsessionarelistedunderneaththeOutputDatabasescontainer.ExpandthiscontainerandthenexpandthecontainerfortheoutputdatabasenamedFrame.odb.

3. ExpandtheMaterialscontainer,andclickthematerialnamedSTEEL.

Allelementsarehighlightedintheviewportbecauseonlyonematerialassignmentwasusedinthisanalysis.

TheResultsTreewillbeusedmoreextensivelyinlaterexamplestoillustratetheXYplottingcapabilityandmanipulatingthedisplayusingdisplaygroups.

Customizinganundeformedshapeplot

Youwillnowusetheplotoptionstoenablethedisplayofnodeandelementnumbering.Plotoptionsthatarecommontoallplottypes(undeformed,deformed,contour,symbol,andmaterialorientation)aresetinasingledialogbox.Thecontour,symbol,andmaterialorientationplottypeshaveadditionaloptions,eachspecifictothegivenplottype.

Todisplaynodenumbers:

1. Fromthemainmenubar,selectOptions Commonorusethe toolinthetoolbox.

TheCommonPlotOptionsdialogboxappears.

2. ClicktheLabelstab.

3. ToggleonShownodelabels.

4. ClickApply.

Abaqus/CAEappliesthechangeandkeepsthedialogboxopen.

ThecustomizedundeformedplotisshowninFigure213(yournodenumbersmaybedifferent).

Figure213Nodenumberplot.



Todisplayelementnumbers:

1. IntheLabelstabbedpageoftheCommonPlotOptionsdialogbox,toggleonShowelementlabels.

2. ClickOK.

Abaqus/CAEappliesthechangeandclosesthedialogbox.

TheresultingplotisshowninFigure214(yourelementnumbersmaybedifferent).

Figure214Nodeandelementnumberplot.

Removethenodeandelementlabelsbeforeproceeding.Todisablethedisplayofnodeandelementnumbers,repeattheaboveprocedureand,underLabels,toggleoffShownodelabelsandShowelementlabels.

Displayingandcustomizingadeformedshapeplot



Youwillnowdisplaythedeformedmodelshapeandusetheplotoptionstochangethedeformationscalefactor.Youwillalsosuperimposetheundeformedmodelshapeonthedeformedmodelshape.

Fromthemainmenubar,selectPlot DeformedShapeorusethe toolinthetoolbox.Abaqus/CAEdisplaysthedeformedmodelshape,asshowninFigure215.

Figure215Deformedmodelshape.

Forsmalldisplacementanalyses(thedefaultformulationinAbaqus/Standard)thedisplacementsarescaledautomaticallytoensurethattheyareclearlyvisible.Thescalefactorisdisplayedinthestateblock.Inthiscasethedisplacementshavebeenscaledbyafactorof42.83.

Tochangethedeformationscalefactor:

1. Fromthemainmenubar,selectOptions Commonorusethe toolinthetoolbox.

2. FromtheCommonPlotOptionsdialogbox,clicktheBasictabifitisnotalreadyselected.

3. FromtheDeformationScaleFactorarea,toggleonUniformandenter10.0intheValuefield.

4. ClickApplytoredisplaythedeformedshape.

Thestateblockdisplaysthenewscalefactor.

5. Toreturntoautomaticscalingofthedisplacements,repeattheaboveprocedureand,intheDeformationScaleFactorfield,toggleonAutocompute.

6. ClickOKtoclosetheCommonPlotOptionsdialogbox.

Tosuperimposetheundeformedmodelshapeonthedeformedmodelshape:

1. ClicktheAllowMultiplePlotStates toolinthetoolboxtoallowmultipleplotstatesintheviewport

thenclickthe toolorselectPlot UndeformedShapetoaddtheundeformedshapeplottotheexistingdeformedplotintheviewport.

Bydefault,Abaqus/CAEplotsthedeformedmodelshapeingreenandthe(superimposed)undeformedmodelshapeinatranslucentwhite.



2. Theplotoptionsforthesuperimposedimagearecontrolledseparatelyfromthoseoftheprimaryimage.

Fromthemainmenubar,selectOptions Superimposeorusethe toolinthetoolboxtochangetheedgestyleofthesuperimposed(i.e.,undeformed)image.

3. FromtheSuperimposePlotOptionsdialogbox,clicktheColor&Styletab.

4. IntheColor&Styletabbedpage,selectthedashededgestyle.

5. ClickOKtoclosetheSuperimposePlotOptionsdialogboxandtoapplythechange.

TheplotisshowninFigure216.Theundeformedmodelshapeappearswithadashededgestyle.

Figure216Undeformedanddeformedmodelshapes.

CheckingthemodelwithAbaqus/CAE

YoucanuseAbaqus/CAEtocheckthatthemodeliscorrectbeforerunningthesimulation.Youhavealreadylearnedhowtodrawplotsofthemodelandtodisplaythenodeandelementnumbers.TheseareusefultoolsforcheckingthatAbaqusisusingthecorrectmesh.

TheboundaryconditionsappliedtotheoverheadhoistmodelcanalsobedisplayedandcheckedintheVisualizationmodule.

Todisplayboundaryconditionsontheundeformedmodel:

1. Clickthe toolinthetoolboxtodisablemultipleplotstatesintheviewport.

2. Displaytheundeformedmodelshape,ifitisnotdisplayedalready.



3. Fromthemainmenubar,selectView ODBDisplayOptions.

4. IntheODBDisplayOptionsdialogbox,clicktheEntityDisplaytab.

5. ToggleonShowboundaryconditions.

6. ClickOK.

Abaqus/CAEdisplayssymbolstoindicatetheappliedboundaryconditions,asshowninFigure217.

Figure217Appliedboundaryconditionsontheoverheadhoist.

Tabulardatareports

Inadditiontothegraphicalcapabilitiesdescribedabove,Abaqus/CAEallowsyoutowritedatatoatextfileinatabularformat.Thisfeatureisaconvenientalternativetowritingtabularoutputtothedata(.dat)file.Outputgeneratedthiswayhasmanyusesforexample,itcanbeusedinwrittenreports.Inthisproblemyouwillgenerateareportcontainingtheelementstresses,nodaldisplacements,andreactionforces.

Togeneratefielddatareports:

1. Fromthemainmenubar,selectReport FieldOutput.

2. IntheVariabletabbedpageoftheReportFieldOutputdialogbox,acceptthedefaultpositionlabeledIntegrationPoint.ClickthetrianglenexttoS:Stresscomponentstoexpandthelistofavailablevariables.Fromthislist,toggleonS11.

3. IntheSetuptabbedpage,namethereportFrame.rpt.IntheDataregionatthebottomofthepage,toggleoffColumntotals.

4. ClickApply.

Theelementstressesarewrittentothereportfile.

5. IntheVariabletabbedpageoftheReportFieldOutputdialogbox,changethepositiontoUniqueNodal.ToggleoffS:Stresscomponents,andselectU1andU2fromthelistofavailableU:Spatialdisplacementvariables.

6. ClickApply.

Thenodaldisplacementsareappendedtothereportfile.

7. IntheVariabletabbedpageoftheReportFieldOutputdialogbox,toggleoffU:Spatial



displacement,andselectRF1andRF2fromthelistofavailableRF:Reactionforcevariables.

8. IntheDataregionatthebottomoftheSetuptabbedpage,toggleonColumntotals.

9. ClickOK.

Thereactionforcesareappendedtothereportfile,andtheReportFieldOutputdialogboxcloses.

OpenthefileFrame.rptinatexteditor.Thecontentsofthisfileareshownbelow.Yournodeandelementnumberingmaybedifferent.Verysmallvaluesmayalsobecalculateddifferently,dependingonyoursystem.

Stressoutput:

FieldOutputReport

Source1

ODB:Frame.odbStep:ApplyloadFrame:Increment1:StepTime=2.2200E16

Loc1:Integrationpointvaluesfromsource1

Outputsortedbycolumn"ElementLabel".

FieldOutputreportedatintegrationpointsforpart:FRAME1

[email protected]+0621294.116E+0631294.116E+0641147.058E+0651294.116E+0661147.058E+0671294.116E+06

Minimum294.116E+06AtElement5

IntPt1Maximum294.116E+06AtElement7

IntPt1

Displacementoutput:

FieldOutputReport

Source1




Loc1:Nodalvaluesfromsource1

Outputsortedbycolumn"NodeLabel".

FieldOutputreportedatnodesforpart:FRAME1

NodeU.U1U.U2Label@Loc1@Loc111.47058E032.54712E03246.3233E122.54712E033735.291E064.66972E0340.5.E3351.47058E035.E33

Minimum46.3233E124.66972E03

AtNode23Maximum1.47058E035.E33

AtNode55

Reactionforceoutput:

FieldOutputReport

Source1


Loc1:Nodalvaluesfromsource1

Outputsortedbycolumn"NodeLabel".

FieldOutputreportedatnodesforpart:FRAME1

NodeRF.RF1RF.RF2Label@[email protected]+0350.5.E+03

Minimum0.0.



AtNode53

Maximum454.747E155.E+03AtNode45

Total454.747E1510.E+03

Arethenodaldisplacementsandpeakstressesintheindividualmembersreasonableforthishoistandtheseappliedloads?

Itisalwaysagoodideatocheckthattheresultsofthesimulationsatisfybasicphysicalprinciples.Inthiscasecheckthattheexternalforcesappliedtothehoistandthereactionforcessumtozeroinboththeverticalandhorizontaldirections.

Whatnodeshaveverticalforcesappliedtothem?Whatnodeshavehorizontalforces?Dotheresultsfromyoursimulationmatchthoseshownhere?

2.3.13RerunningtheanalysisusingAbaqus/Explicit

WewillrerunthesameanalysisinAbaqus/Explicitforcomparison.Thistimeweareinterestedinthedynamicresponseofthehoisttothesameloadappliedsuddenlyatthemidspan.Beforecontinuing,clicktheModeltabintheleftsideofthemainwindowtoswitchtotheModelTree.Clickmousebutton3onModel1intheModelTreeandselectCopyModelfromthemenuthatappearstocopytheexistingmodeltoanewmodelnamedExplicit.MakeallsubsequentchangestotheExplicitmodel(youmaywanttocollapsetheoriginalmodeltoavoidconfusion).Youwillneedtoreplacethestaticstepwithanexplicitdynamicstep,modifytheoutputrequestsandthematerialdefinition,andchangetheelementlibrarybeforeyoucanresubmitthejob.

Replacingtheanalysisstep

Thestepdefinitionmustchangetoreflectadynamic,explicitanalysis.

Toreplacethestaticstepwithanexplicitdynamicstep:

1. IntheModelTree,expandtheStepscontainer.Clickmousebutton3onthestepnamedApplyload,andselectReplacefromthemenuthatappears.

2. IntheReplaceStepdialogbox,selectDynamic,ExplicitfromthelistofavailableGeneralprocedures.ClickContinue.

Modelattributessuchasboundaryconditions,loads,andcontactinteractionsareretainedwhenreplacingastep.Modelattributesthatcannotbeconvertedwillbedeleted.Inthissimulationallnecessarymodelattributeswillberetained.

3. IntheBasictabbedpageoftheEditStepdialogbox,enterthestepdescription10kNcentralload,suddenlyappliedandsetthetimeperiodofthestepto0.01s.

Modifyingtheoutputrequests

Becausethisisadynamicanalysisinwhichthetransientresponseoftheframeisofinterest,itishelpfultohavethedisplacementsofthecenterpointwrittenashistoryoutput.Displacementhistoryoutputcanberequestedonlyforapreselectedset.Youwillusethesetnamedcenter,whichwascreatedearlierwhileassigningtheload.Ifyoudidnotcreatethissetpreviously,thefollowinginstructionsareprovidedforyourconvenience.

Tocreateaset(ifnecessary):

1. IntheModelTree,expandtheAssemblycontaineranddoubleclicktheSetsitem.



TheCreateSetdialogboxappears.

2. Namethesetcenter,acceptthedefaultselectionofGeometry,andclickContinue.

Note:Formeshedpartsyoucandefinesetsthatarebasedoneitherthegeometryorthemesh.Ifyoumodifythemesh,youmustredefineameshbasedset.However,ageometrybasedsetwillupdateautomatically.Forunmeshedpartsonlygeometrybasedsetsareavailable.

3. Intheviewport,selectthepointatthecenterofthebottomedgeofthetruss.Inthepromptarea,clickDonewhenyouarefinished.

Toadddisplacementstothehistoryoutputrequest:

1. IntheModelTree,clickmousebutton3ontheHistoryOutputRequestscontainerandselectManagerfromthemenuthatappears.

2. IntheHistoryOutputRequestsManagerdialogboxthatappears,clickEdit.

Thehistoryoutputeditorappears.

3. UndertheDomainfield,selectSet.Abaqusautomaticallyprovidesalistofallthesetscreatedforagivenmodel.Choosethesetnamedcenter.

4. UndertheFrequencyfield,selectEveryntimeincrementsandsetthevalueofnto1towritetheoutputateveryincrement.

5. IntheOutputVariablesregion,toggleofftheEnergyoutputandclickthearrowtotheleftoftheDisplacement/Velocity/Accelerationcategorytorevealhistoryoutputoptionsfortranslationsandrotations.

6. ToggleonUT,Translationstohavethedisplacementsfortheselectedsetbewrittenashistoryoutputtotheoutputdatabasefile.

7. ClickOKtosaveyourchangesandtoclosethedialogbox.DismisstheHistoryOutputRequestsManager.

Modifyingthematerialdefinition

SinceAbaqus/Explicitperformsadynamicanalysis,acompletematerialdefinitionrequiresthatyouspecifythematerialdensity.Forthisproblemassumethedensityisequalto7800kg/m3.

Toadddensitytothematerialdefinition:

1. IntheModelTree,expandtheMaterialscontaineranddoubleclickSteel.

2. Inthematerialeditor,selectGeneral Densityandtypeavalueof7800forthedensity.

3. ClickOKtoclosetheEditMaterialdialogbox.

Changingtheelementlibraryandsubmittingthejobforanalysis

AswillbediscussedinChapter3,FiniteElementsandRigidBodies,theelementsavailableinAbaqus/ExplicitareasubsetofthoseavailableinAbaqus/Standard.Thus,toensurethatyouareusingavalidelementtypeinyouranalysis,youmustchangetheelementlibraryfromwhichtheelementsareselectedtotheexplicitelementlibrary.Abaqus/CAEautomaticallyfilterstheavailableelementtypesaccordingtotheselectedelementlibrary.Afterchangingtheelementlibrary,youwillcreateandrunanewjobfortheAbaqus/Explicitanalysis.



Tochangetheelementlibrary:

1. IntheModelTree,expandtheFrameitemunderneaththePartscontainer.ThendoubleclickMeshinthelistthatappears.

Abaqus/CAEswitchestotheMeshmodule.

2. Fromthemainmenubar,selectMesh ElementType,selectthesetall(orpicktheentireframeintheviewport),andchangetheElementLibraryselectiontoExplicit.

3. ClickOKtoacceptthenewelementtype.

Tocreateandrunthenewjob:

1. IntheModelTree,doubleclicktheJobscontainer.

2. NamethenewjobexpFrame,andselectExplicitasthesourcemodel.

3. Submitthejob.

2.3.14Postprocessingthedynamicanalysisresults

ForthestaticlinearperturbationanalysisdoneinAbaqus/Standardyouexaminedthedeformedshapeaswellasstress,displacement,andreactionforceoutput.FortheAbaqus/Explicitanalysisyoucansimilarlyexaminethedeformedshapeandgeneratefielddatareports.Becausethisisadynamicanalysis,youshouldalsoexaminethetransientresponseresultingfromtheloading.Youwilldothisbyanimatingthetimehistoryofthedeformedmodelshapeandplottingthedisplacementhistoryofthebottomcenternodeinthetruss.

Plotthedeformedshapeofthemodel.Forlargedisplacementanalyses(thedefaultformulationinAbaqus/Explicit)thedisplacedshapescalefactorhasadefaultvalueof1.ChangetheDeformationScaleFactorto20sothatyoucanmoreeasilyseethedeformationofthetruss.

Tocreateatimehistoryanimationofthedeformedmodelshape:

1. Fromthemainmenubar,selectAnimate TimeHistoryorusethe toolinthetoolbox.

Thetimehistoryanimationbeginsinacontinuousloopatitsfastestspeed.Abaqus/CAEdisplaysthemovieplayercontrolsintherightsideofthecontextbar(immediatelyabovetheviewport).

2. Fromthemainmenubar,selectOptions Animationorusetheanimationoptions toolinthetoolbox

(locateddirectlyunderneaththe tool).

TheAnimationOptionsdialogboxappears.

3. ChangetheModetoPlayOnce,andslowtheanimationdownbymovingtheFrameRateslider.

4. Youcanusetheanimationcontrolstostart,pause,andstepthroughtheanimation.FromlefttorightofFigure218,thesecontrolsperformthefollowingfunctions:play/pause,first,previous,next,andlast.

Figure218Postprocessinganimationcontrols.



Thetrussrespondsdynamicallytotheload.YoucanconfirmthisbyplottingtheverticaldisplacementhistoryofthenodesetCenter.

YoucancreateXYcurvesfromeitherhistoryorfielddatastoredintheoutputdatabase(.odb)file.XYcurvescanalsobereadfromanexternalfileortheycanbetypedintotheVisualizationmoduleinteractively.Oncecurveshavebeencreated,theirdatacanbefurthermanipulatedandplottedtothescreeningraphicalform.Inthisexampleyouwillcreateandplotthecurveusinghistorydata.

TocreateanXYplotoftheverticaldisplacementforanode:

1. IntheResultsTree,expandtheHistoryOutputcontainerunderneaththeoutputdatabasenamedexpFrame.odb.

2. Fromthelistofavailablehistoryoutput,doubleclickSpatialdisplacement:U2atNodexinNSETCENTER.

Abaqus/CAEplotstheverticaldisplacementatthecenternodealongthebottomofthetruss,asshowninFigure219.

Figure219Verticaldisplacementatthemidspanofthetruss.

Note:Thechartlegendhasbeensuppressedandtheaxislabelsmodifiedinthisfigure.ManyXYplotoptionsaredirectlyaccessiblebydoubleclickingtheappropriateregionsoftheviewport.Toenabledirectobjectactions,however,youmustfirstclick inthepromptareatocancelthe



currentprocedure(ifnecessary).Tosuppressthelegend,doubleclickitintheviewporttoopentheChartLegendOptionsdialogbox.IntheContentstabbedpageofthisdialogbox,toggleoffShowlegend.Tomodifytheaxislabels,doubleclickeitheraxistoopentheAxisOptionsdialogbox,andedittheaxistitlesasindicatedinFigure219.

ExitingAbaqus/CAE

SaveyourmodeldatabasefilethenselectFile ExitfromthemainmenubartoexitAbaqus/CAE.

Download - Getting Started With Abaqus

Top Related